Backpacks are widely used by hikers such as travelers or campers to carry various items such as food, water, cook stoves, tents, sleeping bags, first-aid kits, flashlights, rain gear, maps, etc. In order to enjoyably reach out-of-the-way locations, a hiker needs to be physically fit to carrying a backpack which typically weighs about twenty-five to forty pounds when fully loaded with such items.
Various attempts have been made for building strength and endurance for hiking. For example, a hiker can train locally outdoors or in a gym with a fully loaded conventional backpack. However, a fully loaded convention backpack with its large size often calls attention to the hiker when training. In addition, particularly at a gym, a fully loaded conventional backpack limits movement of the hiker to avoid bumping into others or bumping into exercise equipment. In addition, it is often not practical to train with a fully loaded backpack which includes food items, thus requiring a hiker to find and use substitute items, such as metal, disk-shaped, free weights which can easily shift position in a conventional backpack when training.
Other attempts for building strength and endurance for hiking include specially designed exercise backpacks. For example, U.S. Pat. No. 4,332,379 to Bannister discloses a collapsible exercise backpack having a single compartment with an opening at the bottom for receiving a flexible weight carrying member, U.S. Pat. No. 4,944,509 to Snider discloses a weight lifting backpack which accepts standard sized, disk-shaped weights, and U.S. Pat. No. 5,299,999 to Brine discloses a rigid weight pack which receives rectangular-shaped planar weights.
A drawback of such prior art specially designed exercise backpacks is that they fail to provide a similar "feel", e.g., weight positioning and weight distribution compared to a conventional backpack for hiking, thereby limiting a hiker's ability to fully build strength and endurance. Furthermore, a hiker requires, in addition to the specially designed exercise backpacks for training, a separate conventional backpack for carrying items when hiking.
Therefore, there is a need for a low-cost, workout backpack suitable for optimizing training, as well as attachable to a detachable backpack bag suitable for carrying various items when hiking.